iterator_apply

    (PHP 5 >= 5.1.0, PHP 7, PHP 8)

    iterator_apply — Appelle une fonction pour tous les éléments d'un itérateur

    Description

    iterator_apply(Traversable $iterator, callable $callback, ?array $args = null): int

    Appelle une fonction pour tous les éléments d'un itérateur.

    Liste de paramètres

    iterator

    L'object iterator à itérer.

    callback

    La fonction de rappel à appeler à chaque élément. Cette fonction ne reçoit que les arguments args donnés, elle est donc nullaire par défault. Si count($args) === 3, par exemple, la fonction est ternaire.

    Note: La fonction doit retourner true afin de continuer d'itérer à travers l'itérateur nommé par le paramètre iterator.

    args

    Un tableau array d'arguments; chaque élément de args est passé à la fonction de rappel callback comme argument séparé.

    Valeurs de retour

    Retourne le nombre d'itération.

    Exemples

    Exemple #1 Exemple avec iterator_apply()

    <?php
    function print_caps(Iterator $iterator) {
    echo     strtoupper($iterator->current()) . "\n";
    return     TRUE;
    }

    $it = new ArrayIterator(array("Apples", "Bananas", "Cherries"));
    iterator_apply($it, "print_caps", array($it));
    ?>

    L'exemple ci-dessus va afficher :

    APPLES
BANANAS
CHERRIES

    Voir aussi

    • array_walk() - Exécute une fonction fournie par l'utilisateur sur chacun des éléments d'un tableau

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    User Contributed Notes 2 notes

    up
    2
    tezcatl at fedoraproject dot org
    7 years ago
    Each of the arguments required by the function, must be in the array supplied in the third argument to iterator_apply. You can use references too. Example:

    <?php

    function translate_to(string $target_language, Iterator $words, array $dictionaries) {

    $language = ucfirst($target_language);
    $dictionary = $dictionaries[$target_language] ?? 'not found';

    if (    $dictionary === 'not found') {
    echo     "Not found dictionary for {$language}\n";
    return;
    }

    echo     "English words translated to {$language}\n";

    $not_found = [];

    iterator_apply($words, function($words, $dictionary, &$not_found){

    $english_word = $words->current();

    $translated_word = $dictionary[$english_word] ?? '';

    if (    $translated_word !== '') {
    echo     "{$english_word} translates to {$translated_word}\n";
    } else {
    $not_found[] = $english_word;
    }

    return     true;

    }, array(    $words, $dictionary, &$not_found));

    echo     "\nNot found words:\n" . implode("\n", $not_found) . "\n";
    }

    $dictionaries = [
    'nahuatl' => [
    'one' => 'Ze',
    'two' => 'Ome',
    'three' => 'Yei',
    'four' => 'Nahui',
    ],
    ];

    $iterator = new \ArrayIterator(array('one', 'two', 'three', 'four', 'gasoil'));

    translate_to('nahuatl', $iterator, $dictionaries);
    ?>

    English words translated to Nahuatl
    one translates to Ze
    two translates to Ome
    three translates to Yei
    four translates to Nahui

    Not found words:
    gasoil
    up
    2
    tezcatl at fedoraproject dot org
    7 years ago
    Be aware of the proper methods to iterate the specific Iterator you are consuming, as the implementation of the method could vary its behaviour.

    For example, unlike the ArrayIterator, you can't iterate on a SplDoubleLinkedList with current() without using next() on every iteration (and then, only would iterate if you return true at the end of the callable. It is far easier then with LinkedLists use a while($it->valid()) { $it->current(); $it->next(); }

    Let's see:

    <?php

    $ll     = new \SplDoublyLinkedList();

    $ll->push('ze');
    $ll->push('ome');
    $ll->push('yei');
    $ll->push('nahui');

    $ll->rewind();

    $iterations_done = iterator_apply($ll, function(Iterator $it) {

    echo     implode("\t=>", [
    $it->key(),
    $it->current(),
    ucfirst($it->current())
    ]),    "\n";

    return     true;

    }, array(    $ll));

    echo     "Did iterate {$iterations_done} times \n";

    $ll->rewind();

    $iterations_done = iterator_apply($ll, function(Iterator $it) {

    echo     implode("\t=>", [
    $it->key(),
    $it->current(),
    ucfirst($it->current())
    ]),    "\n";

    $it->next();

    return     true;

    }, array(    $ll));

    echo     "Did iterate {$iterations_done} times \n";

    $ll->setIteratorMode(SplDoublyLinkedList::IT_MODE_FIFO | SplDoublyLinkedList::IT_MODE_DELETE);

    var_dump($ll->count());

    foreach(    $ll as $key => $val) {
    echo     "{$key}\t",ucfirst($val),"\n";
    }

    var_dump($ll->count());
    ?>

    Output:

    0 =>ze =>Ze
    0 =>ze =>Ze
    0 =>ze =>Ze
    0 =>ze =>Ze
    Did iterate 4 times
    0 =>ze =>Ze
    1 =>ome =>Ome
    2 =>yei =>Yei
    3 =>nahui =>Nahui
    Did iterate 4 times
    int(4)
    0 Ze
    0 Ome
    0 Yei
    0 Nahui
    int(0)
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